According to a study – “Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses” – published in the British Journal of Nutrition, organic foods are indeed superior.
Demand for organic foods is partially driven by consumers' perceptions that they are more nutritious, the researchers note. However, scientific opinion is divided on whether there are significant nutritional differences between organic and non-organic foods, and two recent reviews have concluded that there are no differences.
In the present study, meta-analyses were carried out based on 343 peer-reviewed publications that indicate statistically significant and meaningful differences in composition between organic and non-organic crops/crop-based foods. Most importantly, the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods, with those of phenolic acids, flavanones, stilbenes, flavones, flavonols and anthocyanins being higher.
Many of these compounds have previously been linked to a reduced risk of chronic diseases, the researchers note, including CVD and neurodegenerative diseases and certain cancers, in dietary intervention and epidemiological studies.
Additionally, the frequency of occurrence of pesticide residues was found to be four times higher in conventional crops, which also contained significantly higher concentrations of the toxic metal Cd.
Significant differences were also detected for some other (e.g. minerals and vitamins) compounds.
There is evidence, said the researchers, that higher antioxidant concentrations and lower Cd concentrations are linked to specific agronomic practices (e.g. non-use of mineral N and P fertilisers, respectively) prescribed in organic farming systems.
In conclusion, the study says, organic crops, on average, have higher concentrations of antioxidants, lower concentrations of Cd and a lower incidence of pesticide residues than the non-organic comparators across regions and production seasons.
